macOS High Sierra ‘root’ security bug reappears if you recently upgraded from macOS 10.13 to 10.13.1

Roman Loyola |
Dec. 3, 2017

You may need to reinstall the security update.

Update 12/1/2017: A Wired report states that users of macOS 10.13 High Sierra who installed the root security update will need to reinstall the update and restart the Mac if the operating system is upgraded to macOS 10.13.1 High Sierra. Apple has details in a support document to see if the update has properly installed.

Update 11/29/17:Apple has released an official fix for the issue via a security update. You can install the update by launching the App Store app, and then click on Updates. Press Command-R to reload the Updates page to see new updates. It will appear as “Security Update,” and you can click on the Update button to install it. Your Mac does not need to restart.

Security is a top priority for every Apple product, and regrettably we stumbled with this release of macOS.

When our security engineers became aware of the issue Tuesday afternoon, we immediately began working on an update that closes the security hole. This morning, as of 8 a.m., the update is available for download, and starting later today it will be automatically installed on all systems running the latest version (10.13.1) of macOS High Sierra.

We greatly regret this error and we apologize to all Mac users, both for releasing with this vulnerability and for the concern it has caused. Our customers deserve better. We are auditing our development processes to help prevent this from happening again.

On Tuesday, a macOS 10.13.1 security issue was revealed—a flaw that allows root access to a Mac without the need for a password. Developer Lemi Orhan Ergin tweeted that anyone can log into a Mac by entering the user name root without a password. The first time you try to login, it won’t work. But if you try it again, you will be granted access. Here’s Erign’s tweet:

Dear @AppleSupport, we noticed a HUGE security issue at MacOS High Sierra. Anyone can login as “root” with empty password after clicking on login button several times. Are you aware of it @Apple?